This randomized, double-blind, placebo-controlled trial (n=80) will study the effects of repeated microdoses of lysergic acid diethylamide (LSD) on creativity and brain activity in healthy adult males. Participants will receive either 10 µg of LSD or a placebo, dissolved in water in 1 ml oral syringes, taken once every three days for a total of 14 doses over a 41-day regimen.
Randomised, double-blind, parallel-group study in healthy male volunteers (25–60 years) comparing repeated microdoses of LSD (10 µg) with matched placebo over 14 dosing sessions across 41 days.
Primary assessments include creative thinking (Alternate Uses Test) and EEG measures (mismatch negativity) at baseline, 2 hours after first administration (Day 1), and 2 days after the final administration (Day 43). Adherence is monitored via participant-recorded dosing videos; a titration amendment permits starting at 5 µg with +1 µg increments to a 10 µg maximum if poorly tolerated.
10 µg LSD every three days for 14 doses (41-day regimen); adherence via video; mid-study titration allowed if not tolerated.
Dissolved in water in 1 ml oral syringes; adherence monitored by participant video. Titration protocol: start 5 µg and increase +1 µg per dose up to 10 µg if required.
Water placebo in identical 1 ml oral syringes, same schedule and adherence monitoring.
Water in 1 ml oral syringes; adherence monitored by participant video.
In a Phase 1 randomized, double‑blind, placebo‑controlled trial of 80 healthy male volunteers, microdosing LSD (10 µg every third day for six weeks) increased objectively measured sleep duration by 24.3 minutes on the night after dosing compared with placebo, with no changes in sleep‑stage proportions or physical activity. The effect, observed across 3,231 nights, is clinically meaningful and unlikely to be explained by placebo.